[ldrhawke]

I've read about a number of different approaches to adding Calcium.

Has anyone tried this approach, and if not what is the possible down side.

Combine in series both a Calcium reactor and a kalkReactor to keep up with calcium demand and control pH. I have just set up my Calcium Reactor and KalkReactor in series, instead of parallel as an experiment.

I am feeding my single stage Calcium Reactor with RO/DI water which has an auto pH control for CO2. The pH in my tank has been dropping from the low Ph output. Instead of adding on a second stage Calcium Reactor to absorb the excess CO2, I set it up to feed through my KalkReactor.

I feed the low pH Calcium Reactor out put into a covered KalkReactor(with stirrer) which then picks up additional calcium, by increasing the pH. and it's output drips drips directly into the sump. I figured the low pH Calcium reactor feed would be similar to adding vinegar to boost the KalkReactor perfomance.

The advantages are only having to control one out put, controlling the low pH, increasing calcium dosing, and doing it in one step. I drip the out put at about 1 drop per second 24/7. This keeps up with my tank evaporation rate.

Comments....good or bad

[Reefland]

Hi LDRHAWKE,

It is actually pretty common to do in order to maintain a decent pH during the night. I have heard of several people doing it and have had great success, I say go for it!

[Poseidon]

If you start with an Acid, and add it to a base solution you usually end up with a precipitate of some sort.... What is that in this case? I don't know, but it seems this may be the proverbial wrench.

Also isn't the norm to feed a Ca Reactor with water from the tank? I am sure saltwater has a different ability to dissolve the reactor media then fresh water would.

I am not trying to rain on the parade, but bring up potential problems. I hope we can get answers to these questions and get a positive result!

[ldrhawke]

Originally Posted by Poseidon

If you start with an Acid, and add it to a base solution you usually end up with a precipitate of some sort.... What is that in this case? I don't know, but it seems this may be the proverbial wrench.

Also isn't the norm to feed a Ca Reactor with water from the tank? I am sure saltwater has a different ability to dissolve the reactor media then fresh water would.

I am not trying to rain on the parade, but bring up potential problems. I hope we can get answers to these questions and get a positive result!

Not raining on the parade...just discussing how things work.

Just the opposite happens.....an acid dissolves a base and puts it into solution. Raising the pH, not dropping it can cause a percipitation snow storm. Isn't that why you inject CO2 into a Calcium reactor? To make the water acidic. If the Calcium reactor has excess CO2 in it's discharge, which makes it acidic, it will help to put the pickling lime (Kalk) into solution. That is also why adding vinegar to Kalk water is recommended to increase it's calcium out put. The discharge will hold a higher Ca concentration by using vinegar and making the water acidic.

Salt water in your tank is already partially saturated with Ca. RO/DI water that is slightly acid from the CO2 has tha ability to dissolve far more new Ca than tank salt water. That is the reason RO/DI water is recommended for a KalkReactor. One problem in using higher flow rates of tank water through a Calcium reactor is you need to add more CO2 to compensate for the larger quantity of tank water used to lower the pH, which in turn can lower the the tank pH. Using RO/Di water will hold more new Ca in solution and can reduce the amount of pH drop in the tank from the excess CO2.

There is no reason, that I know of, not to use RO/DI in a Calcium Reactor other than you can end up having to add more new water than the tank evaporates in keeping up with Ca demand. As long as it doesn't add more water than what evaporates from the tank; which is my reason for putting the two systems in series, it should work just as well; if not better, and it make it easier to keep a tanks pH from slowly dropping.

[golfish]

My only thought on this is you wouldn't be able to keep up with the Ca demand in fully stocked tank...Running tank water though the Ca reactor allows you all you want, your way is limited to evap. You can only satutrate the water so much.

FWIW, I run both on my system.

[ldrhawke]

Originally Posted by golfish

My only thought on this is you wouldn't be able to keep up with the Ca demand in fully stocked tank...Running tank water though the Ca reactor allows you all you want, your way is limited to evap. You can only satutrate the water so much.

FWIW, I run both on my system.

The concept was to increase the Ca concentration of the Kalk by feeding it with low pH water from the Calcuim reactor so that it can be maintained at a higher Ca by only using evaporation make up water.

At some point with enough calcium demand you may be right. Right now my system is maxed out using this method with around 450 Ca and 11 dkh Alk. It will start to snow if it gets any higher, so it is working for me.